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// Copyright 2008 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Utility function for linkifying text.
* @author bolinfest@google.com (Michael Bolin)
*/
goog.provide('goog.string.linkify');
goog.require('goog.string');
/**
* Takes a string of plain text and linkifies URLs and email addresses. For a
* URL (unless opt_attributes is specified), the target of the link will be
* _blank and it will have a rel=nofollow attribute applied to it so that links
* created by linkify will not be of interest to search engines.
* @param {string} text Plain text.
* @param {Object.<string, string>=} opt_attributes Attributes to add to all
* links created. Default are rel=nofollow and target=blank. To clear those
* default attributes set rel='' and target='_blank'.
* @return {string} HTML Linkified HTML text.
*/
goog.string.linkify.linkifyPlainText = function(text, opt_attributes) {
var attributesMap = opt_attributes || {};
// Set default options.
if (!('rel' in attributesMap)) {
attributesMap['rel'] = 'nofollow';
}
if (!('target' in attributesMap)) {
attributesMap['target'] = '_blank';
}
// Creates attributes string from options.
var attributesArray = [];
for (var key in attributesMap) {
if (attributesMap.hasOwnProperty(key) && attributesMap[key]) {
attributesArray.push(
goog.string.htmlEscape(key), '="',
goog.string.htmlEscape(attributesMap[key]), '" ');
}
}
var attributes = attributesArray.join('');
return text.replace(
goog.string.linkify.FIND_LINKS_RE_,
function(part, before, original, email, protocol) {
var output = [goog.string.htmlEscape(before)];
if (!original) {
return output[0];
}
output.push('<a ', attributes, 'href="');
/** @type {string} */
var linkText;
/** @type {string} */
var afterLink;
if (email) {
output.push('mailto:');
linkText = email;
afterLink = '';
} else {
// This is a full url link.
if (!protocol) {
output.push('http://');
}
var splitEndingPunctuation =
original.match(goog.string.linkify.ENDS_WITH_PUNCTUATION_RE_);
if (splitEndingPunctuation) {
linkText = splitEndingPunctuation[1];
afterLink = splitEndingPunctuation[2];
} else {
linkText = original;
afterLink = '';
}
}
linkText = goog.string.htmlEscape(linkText);
afterLink = goog.string.htmlEscape(afterLink);
output.push(linkText, '">', linkText, '</a>', afterLink);
return output.join('');
});
};
/**
* Gets the first URI in text.
* @param {string} text Plain text.
* @return {string} The first URL, or an empty string if not found.
*/
goog.string.linkify.findFirstUrl = function(text) {
var link = text.match(goog.string.linkify.URL_);
return link != null ? link[0] : '';
};
/**
* Gets the first email address in text.
* @param {string} text Plain text.
* @return {string} The first email address, or an empty string if not found.
*/
goog.string.linkify.findFirstEmail = function(text) {
var email = text.match(goog.string.linkify.EMAIL_);
return email != null ? email[0] : '';
};
/**
* @type {string}
* @const
* @private
*/
goog.string.linkify.ENDING_PUNCTUATION_CHARS_ = ':;,\\.?\\[\\]';
/**
* @type {!RegExp}
* @const
* @private
*/
goog.string.linkify.ENDS_WITH_PUNCTUATION_RE_ =
new RegExp(
'^(.*)([' + goog.string.linkify.ENDING_PUNCTUATION_CHARS_ + '])$');
/**
* @type {string}
* @const
* @private
*/
goog.string.linkify.ACCEPTABLE_URL_CHARS_ =
goog.string.linkify.ENDING_PUNCTUATION_CHARS_ + '\\w/~%&=+#-@!';
/**
* List of all protocols patterns recognized in urls (mailto is handled in email
* matching).
* @type {!Array.<string>}
* @const
* @private
*/
goog.string.linkify.RECOGNIZED_PROTOCOLS_ = ['https?', 'ftp'];
/**
* Regular expression pattern that matches the beginning of an url.
* Contains a catching group to capture the scheme.
* @type {string}
* @const
* @private
*/
goog.string.linkify.PROTOCOL_START_ =
'(' + goog.string.linkify.RECOGNIZED_PROTOCOLS_.join('|') + ')://+';
/**
* Regular expression pattern that matches the beginning of a typical
* http url without the http:// scheme.
* @type {string}
* @const
* @private
*/
goog.string.linkify.WWW_START_ = 'www\\.';
/**
* Regular expression pattern that matches an url.
* @type {string}
* @const
* @private
*/
goog.string.linkify.URL_ =
'(?:' + goog.string.linkify.PROTOCOL_START_ + '|' +
goog.string.linkify.WWW_START_ + ')\\w[' +
goog.string.linkify.ACCEPTABLE_URL_CHARS_ + ']*';
/**
* Regular expression pattern that matches a top level domain.
* @type {string}
* @const
* @private
*/
goog.string.linkify.TOP_LEVEL_DOMAIN_ =
'(?:com|org|net|edu|gov' +
// from http://www.iana.org/gtld/gtld.htm
'|aero|biz|cat|coop|info|int|jobs|mobi|museum|name|pro|travel' +
'|arpa|asia|xxx' +
// a two letter country code
'|[a-z][a-z])\\b';
/**
* Regular expression pattern that matches an email.
* Contains a catching group to capture the email without the optional "mailto:"
* prefix.
* @type {string}
* @const
* @private
*/
goog.string.linkify.EMAIL_ =
'(?:mailto:)?([\\w.+-]+@[A-Za-z0-9.-]+\\.' +
goog.string.linkify.TOP_LEVEL_DOMAIN_ + ')';
/**
* Regular expression to match all the links (url or email) in a string.
* First match is text before first link, might be empty string.
* Second match is the original text that should be replaced by a link.
* Third match is the email address in the case of an email.
* Fourth match is the scheme of the url if specified.
* @type {!RegExp}
* @const
* @private
*/
goog.string.linkify.FIND_LINKS_RE_ = new RegExp(
// Match everything including newlines.
'([\\S\\s]*?)(' +
// Match email after a word break.
'\\b' + goog.string.linkify.EMAIL_ + '|' +
// Match url after a workd break.
'\\b' + goog.string.linkify.URL_ + '|$)',
'g');
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